Subjective Workload Measurement: An Aid in Evaluating Flightline Maintenance Systems

Abstract

Armstrong Laboratory, Logistics Research Division performed an evaluation to determine whether flightline maintenance was improved by using a computerized, integrated maintenance information system (IMIS) for different types of users. The laboratory's evaluation overcame several logistical problems common to conducting research outside a laboratory setting. Such problems include obtaining representative subjects, controlling for extraneous variables, and gathering adequate sample data. The present study includes 24 maintenance technicians (12 avionics specialists and 12 crew chief non-specialists). Each subject performed 12 maintenance tasks (6 using electronic and 6 using paper presentation). Subjective workload ratings and objective performance times were measured. Subjective workload (using National Aeronautics and Space Administration-Task Load Index (NASA-TLX)) and objective performance results revealed similar interactions. Using paper-based presentations, crew chiefs gave significantly higher subjective workload ratings than avionics specialists and significantly longer total performance time (e.g., time-to-complete). However, there were no significant differences between the two groups when using electronic-based presentations.